Not Applicable.
Not applicable.
1. Field of the Invention
The present invention is directed to an apparatus for aligning the front wheels of motor vehicles. More particularly, the present invention is directly a an apparatus for bending the front axle of a truck during the wheel alignment process. The degree of required bending is measured by a different apparatus that forms no part of the present invention.
2. Description of the Related Art Including Information Disclosed Under 37 C.F.R. 1.97 and 1.98
The wheels of motor vehicles, particularly the front wheels, must be properly aligned to prevent excessive wear of the tires, which may cause dangerous handling and uneven tread wear, and to insure proper handling of the motor vehicle during driving and to maximize the fuel efficiency of the motor vehicle. As the vehicle is driven, the alignment of the wheels deviates from the manufacturers""s recommended settings, either through routine wear or from striking an obstacle, such as a curb or pothole. The vehicle must then be serviced to return the alignment of the wheels to their recommended alignment.
In the case of heavy trucks in particular, such as the tractor of a tractor-trailer rig, the wheels are brought into proper alignment by bending the front axles while the various alignment criteria, such as camber and so forth are monitored by an alignment measuring apparatus. This alignment apparatus forms no part of the present invention, which is solely directed to providing an apparatus for actually holding and bending the axles.
In related devices made in the past, conventional cylindrical apertures were used to provide bolt holes to hold an assembly together. This apparently worked for light trucks from the early to mid-twentieth century. As trucks have become heavier and stronger, however, the forces required to bend the axles of modern heavy trucks are too great for parts fastened together with cylindrical apertures to retain the fasteners and the bolts and connectors bend, rendering them unsuitable for aligning the front wheels of modern heavy trucks.
Therefore, the front axles of most large trucks are currently bent by a complex and expensive apparatus. This apparatus requires a concrete-walled pit below the floor of the garage with heavy anchors embedded into the floor of the pit. Heavy chains are fastened to these anchors, then wrapped around the axle in the desired location and pulled tight by one or more hydraulic rams that exert sufficient force on the axle to bend it the desired amount, as indicated by the alignment measuring apparatus. The chains are subject to snapping while under this tension. When a chain breaks, it flails about wildly with great energy and can easily cause serious property damage or personal injury. Therefore, current pit-oriented alignment systems are expensive and dangerous.
In the decades prior to about 1949, truck alignment was accomplished in some cases by providing a pair of spaced apart vertical struts each having a lower end fixed to a beam on the floor or in a pit. The upper ends of the struts retain a yoke that is placed over the top surface of the axle at a desired location along the length of the axle. Typically, one strut and yoke is attached to each front axle, but both struts and yokes can be attached to the same axle if desired. A hydraulic ram or jack is placed on the beam and presses upwardly on the axle at a desired location. The axle is bent in upward, with an effect on the wheel end that is determined by the relative placements of the strut and the ram and which may be either up or down. The struts and the ram are moved from place to place and the axle bent according to the needs of a particular alignment job until the wheels are brought into alignment. Such a system is disclosed in U.S. Pat. No. 1,739,891 issued to Dimmick on Dec. 17, 1929.
In other related apparatus, the struts are temporarily connected to the outer ends of the axles, as in U.S. Pat. No. 2,830,789 issued to MacMillian on Apr. 15, 1958.
This type of wheel alignment apparatus seems not to have been the subject of new patents since about 1958, with most patents in this field having appeared much earlier. Nor does it appear that this type of apparatus is in current use, having been supplanted by the chain and ram in a pit alignment apparatus described above. It is believed that this change in typical alignment apparatus has occurred because bending modern truck axles requires more force than such systems can withstand.
The modem usage of systems that require a pit in the garage seriously restrict the numbers of facilities that can offer wheel alignment services for large trucks because many shops cannot afford the cost of a pit and the associated equipment and necessary insurance or do not have space for one.
Therefore, there is a need for a wheel alignment apparatus for bending axles on motor vehicles that is relatively inexpensive, that does not require used of a concrete-lined pit, that eliminates the possibility of chains snapping under great force and thereby reduces insurance costs as well as the possibilities of personal injury and property damage from snapping chains, that is simple to use and that is durable and withstands the greater force requirements of large modern trucks.
Accordingly, it is a primary object of the present invention to provide a wheel alignment apparatus for bending front axles on motor vehicles that is relatively inexpensive.
It is another object of the present invention to provide a wheel alignment apparatus for bending front axles on motor vehicles that does not require use of a concrete pit.
It is another object of the present invention to provide a wheel alignment apparatus for bending front axles on motor vehicles that eliminates the possibility of chains snapping under great force and thereby reduces insurance costs as well as the possibilities of personal injury and property damage from snapping chains.
It is another object of the present invention to provide a wheel alignment apparatus for bending front axles of motor vehicles that is simple to use.
It is another object of the present invention to provide a wheel alignment apparatus for bending front axles of motor vehicles that is durable and withstands the greater force requirements of large modem trucks.